INFO: task kworker/u8:17:3122 blocked for more than 145 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:17 state:D stack:21240 pid:3122 tgid:3122 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5388 [inline][ 1001.773343][ T37] __schedule+0x16ec/0x5620 __schedule+0x16ec/0x5620 kernel/sched/core.c:7189[ 1001.773343][ T37] __schedule+0x16ec/0x5620 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 rxrpc_destroy_all_calls+0x44e/0x570 net/rxrpc/call_object.c:754 rxrpc_exit_net+0x6f/0xc0 net/rxrpc/net_ns.c:112 ops_exit_list net/core/net_namespace.c:199 [inline] ops_undo_list+0x49f/0x940 net/core/net_namespace.c:252 cleanup_net+0x56e/0x800 net/core/net_namespace.c:702 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by khungtaskd/37: #0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/1:1/42: 4 locks held by kworker/u8:13/1199: 4 locks held by kworker/u8:15/1288: 3 locks held by kworker/u8:17/3122: #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000f397c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000f397c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8f340fa0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 3 locks held by dhcpcd/5269: 2 locks held by getty/5359: #0: ffff8880367840a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 4 locks held by kworker/1:7/6002: 4 locks held by syz-executor/10193: 2 locks held by syz-executor/10194: 1 lock held by udevd/10432: #0: ffff888037666480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 2 locks held by syz-executor/10529: 1 lock held by udevd/10536: #0: ffff888037666480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 1 lock held by udevd/10729: #0: ffff888037666480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 2 locks held by syz-executor/11432: 1 lock held by dhcpcd/11526: #0: ffff888087a0c358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff888087a0c358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3204 4 locks held by syz.8.1144/11528: 1 lock held by dhcpcd/11529: #0: ffff88802e3ec358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88802e3ec358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3204 1 lock held by dhcpcd/11530: #0: ffff888028f9e358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff888028f9e358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3204 1 lock held by dhcpcd/11531: #0: ffff888063372358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff888063372358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3204 1 lock held by dhcpcd/11533: #0: ffff888083d86358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff888083d86358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3204 2 locks held by dhcpcd/11535: 1 lock held by dhcpcd/11536: #0: ffff888043b88358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff888043b88358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3204 1 lock held by dhcpcd/11537: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11535 Comm: dhcpcd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:check_preemption_disabled+0x29/0xe0 lib/smp_processor_id.c:19 Code: 90 55 41 57 41 56 53 65 8b 05 07 2e 4e 07 65 8b 0d fc 2d 4e 07 f7 c1 ff ff ff 7f 74 0c 5b 41 5e 41 5f 5d e9 19 aa 03 00 cc 9c <59> f7 c1 00 02 00 00 74 ea 65 4c 8b 3d ae 2d 4e 07 41 f6 47 2f 04 RSP: 0018:ffffc90004d07558 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 0000000080000000 RDX: 0000000000000000 RSI: ffffffff8d61af6a RDI: ffffffff8ba75be0 RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000004 R12: 0000000000000246 R13: ffff88802f219ec0 R14: ffff88802fb46bb0 R15: ffff88802fb46bb0 FS: 00007f18187e5780(0000) GS:ffff888126183000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f181875de9c CR3: 0000000043aee000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline] lock_is_held_type+0x5a/0x150 kernel/locking/lockdep.c:5939 lock_is_held include/linux/lockdep.h:249 [inline] mt_locked lib/maple_tree.c:-1 [inline] mt_slot lib/maple_tree.c:715 [inline] mas_slot lib/maple_tree.c:748 [inline] mas_get_slot lib/maple_tree.c:6406 [inline] mas_validate_gaps lib/maple_tree.c:-1 [inline] mt_validate+0x2578/0x4200 lib/maple_tree.c:6950 validate_mm+0xd4/0x4c0 mm/vma.c:652 vms_complete_munmap_vmas+0x9b1/0xc60 mm/vma.c:1364 do_vmi_align_munmap+0x3bd/0x4d0 mm/vma.c:1604 do_vmi_munmap+0x252/0x2d0 mm/vma.c:1652 __vm_munmap+0x22c/0x3d0 mm/vma.c:3285 __do_sys_munmap mm/mmap.c:1079 [inline] __se_sys_munmap mm/mmap.c:1076 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1076 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f18189f42e7 Code: 00 00 00 b8 0a 00 00 00 0f 05 48 3d 01 f0 ff ff 73 01 c3 48 8d 0d c9 3f 01 00 f7 d8 89 01 48 83 c8 ff c3 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8d 0d a9 3f 01 00 f7 d8 89 01 48 83 RSP: 002b:00007ffc1c4f8368 EFLAGS: 00000206 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 0000563e83a1a3f0 RCX: 00007f18189f42e7 RDX: 0000000000000002 RSI: 0000000000061018 RDI: 00007f1818724000 RBP: 00007ffc1c4f8470 R08: 0000000000000030 R09: 0000563e83a1afa0 R10: 00007ffc1c4f82a0 R11: 0000000000000206 R12: 00007ffc1c4f83b8 R13: 00007f1818a07000 R14: 0000563e83a1a3f0 R15: 0000000000000000